In a bowl, combine garlic, ginger, soy sauce, sake, mirin, sesame oil, sugar, pepper, cayenne, and salt.
Add chicken pieces and mix well. Marinate for at least 1 hour.
Heat canola oil in a deep pan to 170°C (340°F).
Coat each chicken piece evenly with potato starch.
Fry the chicken in batches for 5–6 minutes or until golden and crisp.
Remove and drain on a wire rack or paper towels.
Let it rest for 2–3 minutes before serving.
Serve hot with optional dips or sides like salad or rice.